In a common view, the scientific enterprise has three distinct parts or branches: the humanities, the social sciences, and the natural sciences. For some purposes, this is a useful way of carving up the field of science, but for other purposes a rigid distinction may prevent cross-fertilization. In Part IV, I shall argue that the social sciences can benefit from the biological study of human beings and other animals. In this chapter I argue that the humanities and the social sciences have more in common than is usually assumed. In particular, I shall try to show that interpretation of works of art and explanation are closely related enterprises. To understand a work of art is to explain it in terms of the antecedent mental states of its creator. A successful work of art is one that can be given a rational-choice explanation. At the same time, I shall argue against what one might call “interpretation by consequences,” a phrase that will be clarified later on. The account I shall offer does not cover all art forms. Even within literature, to which I shall limit myself, it makes sense only for classical (pre-1850) novels and plays, defined by the tacit convention that the events and characters that are described could have been real.

Consider first rationality as a motive of the characters in fiction or plays. A classical problem in literary criticism is why Hamlet delays taking revenge for his father's death. Many explanations have been offered.